4" or 5"?
 

I want to put a turbo back straight pipe exhaust but im not sure if I should go with a 4" or 5" exhaust. Im not pushing a lot of power out of my truck yet but once I get a smarty, gauges, new clutch, turbo upgrade, head studs, and intercooler, I will probably be pushing over 500 horses hopefully. Would it be a bad thing to get a 5" exhaust before Im cranking out 500hp or will it matter? Or should I just get a 4"? Also, if I get an aluminized exhaust and get a muffler delete pipe made of stainless steel for free, would it make the exhaust sound funny or different? Should I just spend the $40 on an alumized piece for the exhaust? Thanks for all help.

If you plan on a single turbo, stick with the stock system (already 4"). With the cat and muffler delete, your going to have a lot of drone.

put a 5" turbo back on it you can get a full straight pipe from one of the sponsors for like $300. put a 2gen manifold on it to sounds alot better.

Go with a 5" they sound sweet on a CR.

im running a 4" downpipe into 5" exhaust straight into my 5" stacks no muffler or cat and i love the sound of it

I could go either way but my biggest concern is a loss of power from the 5". Is that a possibility? I dont plan on running twins for quite a while and im just going to get a single turbo replacement.

On a stock engine you could lose backpressure but a 4" down pipe should create enough restriction then from their go with the 5" pipe

Our 5" 04+ Cummins Kits include a Full 5" Down Pipe. You dont have to worry about Backpressure on a Turbo Charged Diesel.

The 5" would be fine then. I would save money actually because once I put a smarty and a turbo upgrade with some other little modifications I will be pushing almost or more than 500hp. Thanks guys!

i had a 5" magnaflow on my '05, very nice system, but forget about the cell phone if your hauling anything. other than that, sounded good